Automatic key cutter



J1me 1964 w. R. G. HAGGSTROM 3,138,999

AUTOMATIC KEY CUTTER 5 SheetsSheet 1 W INVENTOR alter srom MM A154 ATTORNEY Filed March 27, 1962 June 30, 1964 w R HAGGSTRQM 3,138,999

AUTOMATIC KEY CUTTER 5 Sheets-Sheet 2 Filed March 27, 1962 INVENTOR Hayysrom 6W A421 ATTORNEY w. R. G. HAGGSTROM 3,138,999

June 30, 1964- AUTOMATIC KEY CUTTER 5 Sheets-Sheet 5 Filed March 27, 1962 NVENTOR a 6' Tom Willie! B.

4' ATTORNEY June 1964 w. R G. HAGGSTROM 3,138,999

AUTOMATIC KEY CUTTER 5 Sheets-Sheet 4 Filed March 27, 1962 INVENTOR 0 AW ATTORNEY June 30, 1964 w, R. ca. HAGGSTROM 3,138,999

AUTOMATIC KEY CUTTER Filed March 2'7, 1962 5 Sheets-$heet 5 I INVENTOR mlzegfi fiay sfrom/ A/Z/ ATTORNEY United States Patent 3,138,999 AUTDMATIC KEY CUTTER Walter R. G. Haggstrom, Westminster, Mass, assignor to Independent Lock Company, Fitchburg, Mass, a corporation of Massachusetts Filed Mar. 27, 1962, Ser. No. 182,854 6 Claims. (Cl. 90- 1345) This invention relates to a key duplicating device, and more particularly to a copying device for cutting or bitting the blade portion of a key blank to form thereon the tumbler operating combination corresponding to the combination of a selected key. More particularly, this invention relates to a key cutting device wherein a tumbler operating pattern formed'on the blade portion of a selected key may be duplicated or reproduced on a selected key blank. This invention is a continuation in part of my pending application Serial No. 133,957 and filed August 25, 1961. a

As in the case of the aforementioned copending application, this invention relates to a key duplicator which is substantially automatic and fool-proof in operation whereby the same may be successfully operated by a person having no prior experience in the handling of key cutters. Moreover, the simplicity of the operation of the machine is such as to. render possible its use in a key vending device or as an element in the merchandising of key blanks whereby selection of, or delivery of a blank to be cut, as from or by a key blank vending ma chine or the like and the introduction of said blank manually or automatically into the key cutting machine clamp, together with the key to be duplicated, will auto matically result in cutting a perfect copy.

In its more specific phases, this invention relates to an automatic key cutter having a novel operating assembly whereby the steps heretofore necessarily manually effected are effected automatically.

More specifically, this invention relates in one aspect to novel key blank and pattern key clamp means'for receiving and maintaining the key and key blank during the cutting operation.

7 Accordingly, it is an object of this invention to provide a key cutting machine which is largely automatic in its operation. A further object of this invention is to provide a novel key cutting device poweredv by a motor mounted in such manner that the weight thereof augments the key milling action of the cutter element, and which motor is additionally utilized to drive at slow speeds a shaft journalled on the frame of the cutterdevice, to

i which shaft is secured plural operating means for automatically and in timed sequence carrying out the functions hereinafter described.

Still a further object of this invention is the provision of a key cutting device having clamp means which include key seating elements and key gripping elements, the first mentioned elements being effective to secure accurate initial positioning of the key and key blank, and the second mentioned elements being effective to supplant the holding influence of the first mentioned elements during the actual cutting of the key.

A further object of this invention is to provide a clamp mechanism for a key cutter wherein a key blank and a patterned key will be securely held during the cutting operation, notwithstanding the key and key blank are of varyin g thickness.

Still a further object of this invention is to provide in a key cutting device clamp means for the key blank and pattern key which assure that the pattern key and key blank are accurately aligned in the clamps before initiation of the cutting cycle.

A further and principal object of this invention is the provision of a key cutter which may be used in conjunction with or as part of a key cutting device by persons unskilled in the art of locksmithing and unaccustomed to the operation of a key cutting machine and the requirements for accurate reproduction of cut keys.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, reference is made to the accompanying drawings, forming a part hereof,-in which- FIGURE 1 is a perspective view of a key cutting device in accordance with the invention with portions thereof spaced from their normal operative positions for clarity of illustration. 7

' FIGURE 2 is a vertical sectional view of the key cutter.

FIGURE 3 is a vertical section taken on the line 3-3 of FIGURE 2. 7

FIGURE 4 is a horizontal section taken on the line 44 of FIGURE 2 with the key cutter in the initial or loading position thereof.

FIGURE 5 is a section in accordance with FIGURE 4 taken at an advanced stage of operation of the cutter device.

FIGURE 6 is a magnified perspective view of the key blank clamp member and associated mechanism;

FIGURE 7 is a vertical section-taken on the line 7--7 of FIGURE 6.

FIGURE 8 is a fragmentary plan view of an embodiment of the invention;

FIGURE 9 is a fragmentary perspective view of hold down operating mechanism in accordance with an embodiment of the invention;

FIGURE 10 is a front elevational view of the embodiment of FIGURE 9;

FIGURE 11 is a magnified section taken on line 11-11 of FIGURE 9.

An understanding of the invention herein is facilitated 1 by a brief description of the general construction and operation of the cutter device. The device generally includes a base or frame having track or guide portions thereon and having parallel abreast clamping receptacles for a key and key blank. A carriage is shiftably mounted on the track or guide portions of the frame to permit linear'movement of the carriage toward and away from the key seats or receptacles. A key duplicator head having the usual tracer and cutter elements is mounted to the carriage for pivotal movement on an axis normal to the direction of movement of the carriage. The key cutter is driven. by a motor suitably mounted on the duplicator head in such position that the weight of said motor aids in the key cutting operation by urging the cutter against the key blank. The motor drive shaft is linked by extensible and flexible shaft elements to a speed reducer member fixed to the frame and driving a cross shaft having its axis of rotation aligned normal to the direction of the track or guide means of the frame.

The cross shaft which rotates at a very slow speed during the operating cycle of the key cutter, carries a plurality of cam members. The carriage includes a follower portion, the entire carriage being spring biased whereby said follower portion is engaged against one such cam member, the coaction of such cam and follower serving to shift the carriage toward and away from the key and key blank receptacles. The key receptacles are each provided with a clamp jaw and a hold-down lever serving respectively to apply lateral and downward pressure to the key shank portions. Initially, the key and key blank when inserted into receptacles, are urged into proper position therein by the yielding pressure of the hold-down and clamp jaw elements. The hold-downand clamp jaw elements in addition are provided with follower portions which coact with other cams carried by the cross shaft so that'on initiation of a cutting cycle the hold-down levers are pivoted clear of the key shank portion to permit cutting and tracing of the pattern on such portion, the clamp jaw members being simultaneously locked into gripping position of the key whereby the yieldable pressure on the shank by the jaw is supplanted by a considerable locking pressure to maintain the key in position during the cutting cycle. At the completion of the cutting cycle the holddown and clamp jaw members are released by their respective follower means to their initial position whereat they are yieldably biased against the shank portions of the key and key blank. Optionally, but preferred, the key cutter device is provided with electrical cycle initiating means, as described and claimed in my copending application aforesaid whereby the cutting cycle is begun automatically responsive to proper insertion of the key and key blank into the appropriate receptacles.

In accordance with the invention, I provide a frame member including a base portion 11 to which are fixedly mounted the seats or receptacles 12, 13 for the key blank and pattern key respectively. The frame 10 may be secured to the top of a work bench, or the like. However, where the cutting device is not to be used in a locksmith establishment, or where the cutter is to be used as or in conjunction with a vending device, the frame may be enclosed within an appropriate container or cabinet having formed therein access slots registering with the key slots 14 and 15 of the key blank and pattern key seats 12 and 13, respectively.

A pair of track or guide elements 17, 18 are fixed to base 11 to lie parallel with each other, with the base, and with keyway slots 14 and 15. In the illustrated embodiment of this invention, the guide element 17 comprises a fiat upwardly directed wall and the element 18 comprises a rod-like generally cylindrical member, it being understood, however, that various other forms of track or guide means may be employed without departing from the spirit of the invention A carriage member is linearly slidably mounted on the guides 17 and 18, the said carriage comprising a generally 'U-shaped assembly including parallel opposed side walls 31 and 32; Depending from the underside carriage 30 are yoke members 33 recessed at the underside thereof to provide a complemental sliding fit on the guide rod 18. The carriage 30 is provided in addition with depending foot portions 35 in laterally spaced relation to the yokes 33 the portions 35 registering with and riding on the guide elements 17. From the foregoing it will be seen that the carriage 30 is permitted a range of sliding movement forwardly and rearwardly along the guide means 17 and 18, a recessed portion 34 of the yokes 33 acting then to prevent lateral movement of the carriage 30 with respect to the guide members aforesaid. The side walls 31, 32 of the carriage 30 are provided in addition with opposed trunnion portions 37, 38 respectively, which portions extend toward each other and are coaxially aligned. Fixed to the carriage 30 and extending rearwardly therefrom is a carriage follower bar 39 having fixed to the rearmost end thereof a carriage follower shoe 40 for purposes hereinafter described.

A duplicator head is pivotally mounted to the carriage 30 on trunnions 37, 38 fixed to the walls 31, 32 of said carriage. Head 50 comprises a rigid support shell 51 of a generally box-like conformation, the bottom of said shell 51 being open. The side walls 52, 53 of the shell 51 are provided with bearing notches 54 and 55 respectively which, in the assembled position of the head 50, rest respectively on trunnions 37 and 38 to provide a pivotal connection between the head 50 and the carriage 30 previously described. The motor M is bolted or otherwise secured to the underside of the shell 51, the drive shaft D of said motor extending through the rear wall 56 of the shell 51. The motor M is mounted in such a manner as to align the center of gravity thereof forwardly of the notches 54, 55 whereby, when the notches 54, 55 are seated on trunnions 37, 38 the weight of the motor will tend to pivot the head 50 forwardly so that the forward wall 57 thereof is urged downwardly under the influence of said motor. The cutter drive shaft 58 is journalled in the forward and rearward walls 57, 56 of the shell 51, a cutting or milling wheel 59 being mounted on the portion of shaft 58 extending forwardly on the wall 57. A pully 60 is fixed to the shaft 58 at a point rearwardly of the rear wall 56 of the shell 51, said pulley 60 being linked to a pulley 61 fixed to drive shaft D of the motor M by a belt 62. A pattern tracer stylus 63 is adjustably secured to the front wall 57 of the shell 51 by adjustable clamp member 64 permitting a vertical adjustment of the stylus 63 with respect to said clamp. Also, in the normal operation the clamp 64 is adjusted so that the apex 65 extends beneath the carriage 50 exactly the same distance as the lowermost point of the periphery 66 of the wheel 59 extends below said carriage. Optionally, but preferably, a pair of tension springs 68, 69 are secured to the side walls 52, 53 of the head 50 at their upper ends and that their lower ends are fixed to the frame base 11 through eyes 11', 11 whereby the downward pivoting force exerted on the forward end 57 of the head 50 by the weight of motor M is implemented. Downward pivotal movement of the head 50 toward the carriage 30 is limited by the provision of a depending leg member 67 having fixed thereto a roller wheel 67a engaging against the horizontally disposed body portion of said carriage in the inoperative position of the device (FIG. 2).

Fixed to the base 11 of frame 18 is a speed reducer gear assembly 70 having an in-put drive element 71 which when rotated, rotates in turn a square cross shaft member 72 having bearing portions journalled in the speed reducer assembly 70. The shaft 72 lics parallel to the base 11 and normal to the guide track members 17 and 18. The speed reducer mechanism 78 is of conventional design and need not be described further except to indicate that the gear ratio of the illustrated embodiment is calculated to produce one revolution of the shaft 72 for each 5800 revolutions of the in-put member 71. The 5800 to 1 ratio of the gear assembly aforesaid is optional and it will be understood by those skilled in the art that such ratio should be varied dependent upon the horsepower rating and speed of revolution of the motor M selected for use in the cutter device.

It will be understood that in the course of normal op eration, the head 50 carrying motor M will move both linearly and pivotally with respect to the speed reducer member 70. Accordingly, in order to drive the in-put 71 of said speed reducer a driving connection must be made between the shaft D of the motor M and the in-put 71 of the speed reducer, which connection is both flexible and extensible. In the illustrated embodiment the speed reducerd in-put 71 is provided with an axially extending channel 74 having eccentric drive recesses '73, 73. Fastened to the drive shaft D of motor M behind pulley 61 is a flexible drive shaft element 75 which comprises a coil spring 76 having fixed to the rearward end thereof a spline shaft 77 with laterally extending eccentric lobes 78, 78. The spline shaft 77 is slidable within the channel 74 of the speed reducer in-put 71, the lobes '78, 78 of said spline shaft forming a driving connection with the eccentric recess portions 73, 73 of channel 74. It will thus be appreciated that as the head 50 moves away from the speed reducer 70 the shaft 77 will slide within the channel 74 accommodating such linear movement, pivotal movement of the head 50 with respect to said speed reducer being accommodated by the coil spring 76. It will be readily understood by those skilled in the art that other forms of flexible connectors such as rubberized or composition elements may be substituted for the coil spring 75 and that universal couplings are equally adaptable for this purpose. Likewise, other arrangements slidably linking the speed reducer in-put with the out-put of the universal coupling may be usefully employed.

rate initial positioning, and locking clamp jaw portions effective during the cutting cycle for securely clamping said key blank and pattern key in said properly seated position. Since the clamping and operating apparatus associated with the vise or receptacle 12 is identical with that associated with the pattern key receptacle 13 only the former said apparatus will be described, it being understood that the apparatus associated with the vise 13 operates simultaneously and in the same manner as the apparatus for the former said vise. The vise 12 includes as a portion of the key Way slot 14 a lower or horizontally disposed wall 81 and a fixedside wall portion 81 normal to the wall 819. A clamp jaw member 82 is pivotally mounted on shaft 83 to be shiftable toward and away from the wall 31 a compression coil spring 84 being interposed between the leg portion 35 of the jaw 82 and a portion of the vise 12 to urge clamping face 86 of said jaw resiliently against the wall 81 when no key is positioned in the clamp. The leg portion 85 of the clamp jaw 82 is provided with a later-ally extending hardened steel ball 87 fixed within a recess 83 formed in said leg. The upright portion 89 of the vise 12 is likewise provided with a hardened ball 919 in opposed relation to the ball 87 and similarly seated within a recess 91 formed in the leg 89.

A hold-down lever 100 is provided for seating the base of an inserted'key blank against the lower wall portion 811 of the key way slot 14. The lever 11% fixed to a shaft 161 is horizontally disposed and rotatably journalled in the bearing aperture 1112 of the vise 12, said shaft at its rearward end being journalled in a vertical bracket 1113 fixed to the base 11 of the frame. A torsion spring 1114 is secured at one end 105 to the bracket 103 the other end 106 of said spring being fixed to a boss 1117 non-rotatably mounted to the shaft 1111. The spring 1134 is mounted under tension and thus normally serves to urge the shaft 101 counter-clockwise (as. best seen in FIGS. 1 and 7) thereby resiliently urging the hold-down portion 108 of the lever 161d downwardly and in registry with key slot 14. As best seen in FIG. 6, the clamp face 36 and/the side wall portion 81 are rocessed or hollowed at 86a and 81:: respectively to provide a better gripping action particularly where a slightly bent or nickel key or key blank is encountered. The jaw 86, side wall portion 81 and bottom wall portion 80 are provided with chamfered or beveled leading portions 3%, 81b, 86b to facilitate insertion of the key and key lank into the key way slot 14. As previously noted the jaw $2 is yieldably urged by spring 84 against the sidewall 81 of the key blank slot 14. The pressure exerted by the spring 34 is necessarily relatively light in order to permit ready insertion of a key blank into the slot 14 and accordingly such pressure will not be sufficient to maintain the key blank against movement withinthe slot during the cutting operation. In order to lock the clamp jaw as against the key blank thereby fixedly securing the latter between the jaw 86 and the wall 81, there is provided a locking wedge 116' interposed between bracket 89 of the key receptacle 12 and the leg .8

of clamp jaw member 82. The wedge 110 is disposed between the ball members 913 and 87 so that when said wedge is shifted rearwardly in a manner hereinafter described, the jaw 86 is forced toward the wall 81 tightly clamping the key within the key way slot 14. Locking wedge 11%) is secured at its rearward end to a clamp follower rod 111 horizontally slidably supported by brackets 112 and 113 extending upwardly from base 11. A relatively heavy compression spring 114 is interposed between the rear face of bracket 112 and a collar 115 fixed to the rod 111. A clamp follower shoe 116 is secured to the rearward end of the rod 111. It will be understood from the description of the above that the compression spring 114 will tend to shift the rod 111 and its associated locking wedge 11h rearwardly or to the jaw-locking position thereof.

The wedge is normally maintained in a forward or clamp jaw releasing position by the engagement of a follower shoe 116 with the periphery of clamp jaw operating cam 117 which is fixed to the cross shaft 72 to rotate therewith. As best seen in FIGS. 1 and 7, the cam 117 has a peripheral portion eccentric with respect to the axis of rotation of shaft 72 and including a gradually increasing rise portion extending throughout substantially the entire periphery of said cam and terminating at a sector 11% which comprises a peripheral portion of said cam spaced furthest from the axis of rotation of shaft 72.

The cam 11 7 is aligned with the axis of shaft 111 and when the high sector 118 of the cam is aligned with the follower shoe 116 the rod 111 and its associated wedge 11%? will have been shifted to the forwardmost or clamp jaw releasing position thereof. The cam 117 is provided in trailing position of sector 11% with a sharp drop or ledge portion 119. From the above it will be readily recognized as the shaft 72 rotates, the sector 118 will be shifted from registering position with the shoe 116 and the shoe will be entirely released from the periphery of said cam when the ledge or cut-out sector 119 is in registry with said shoe 116. When this release occurs the compressed spring 114 acting against collar will snap or project the entire rod 111 rearwardly driving the wedge 11% sharply between the ball members 87 and 90 and thus locking the jaw 32 in clamping position against the key inserted between said jaw and the wall 81 under the maintaining pressure of spring 114. stood that upon further rotation of shaft 72 the gradually inclined periphery of the cam 117 will again be brought into contact with the shoe 1116 again shifting the follower rod 111 and its associated wedge 111) forwardly and releasing the jaw 82 from the locking engagement of the wedge. By reason of the shallow incline of the faces of the wedge 11d and the sudden releasing action of the cam 117 on follower shoe 116 a very considerable clamping force is developed to provide a positive locking action against the key.

It will be readily understood from the positioning of the duplicator head previously described that the key blank and key must be inserted in the slots 14 and 15 respectively with the bitted tumbler operating edges of the key blade disposed upwardly. In order for the tracer and the cutter elements of the duplicator head to engage said upper elements of the key and key blank, it is necessary to shift the hold-down portions 108 of hold-down levers 1% clear of the slots 114, 115 to expose the upper blade portions to the operative elements of duplicator head. For this purpose there is fixed to the rear end of shaft 101 a disc member 120 having mounted thereon a follower pin 121 eccentrically with respect to the axis rotation of the shaft 1101. A drum cam 122 is fixed to the cross shaft 72 to rotate therewith, cam 122 being provided with lateral cam surfaces adapted to engage the pin 121 and by the angular camming movement imparted by the cam to the pin to rotate shaft 181 against the action spring 1114 thereby causing the hold-down lever to be cleared from above the key retaining slots and permitting operative engagement with the key and key blank of the cutter and duplicating tracer. A gradual rise surface 123 is formed on the cam 122 and as the shaft 72 rotates counter-clockwise, as seen in FIG. 1, the surface 123 engages behind pin 121 shifting the latter against the pressure of spring 164 until said pin lies against the generally flat inner peripheral portion 124 of the cam 122. When the pin 121 lies against the surface 124 the hold-down lever will remain in the key way slot clearing position by the engagement of the pin with said peripheral surface. When the earn 122 is rotated nearly afull revolution a gradual decline portion 125 is brought into registry with the pin 121, torsion spring 1634- being then per- It will be under mitted to rotate the shaft 101 causing the hold-down lever to be returned to its initial downward position. It should be understood that the operation of the cams 117 and 122 are coordinated whereby preferably the locking Wedge 110 is released by the cam 117 to jaw locking position just prior to the lifting of hold-down lever 100 by the coaction of cam 122 and follower pin 121.

The carriage 30 is urged rearwardly or toward its starting position by tension springs 130, 130, one end of each of such springs being secured to said carriage, the other end of the springs being fixed to the base 11. An eccentric drive cam 131 is fixed to the cross shaft 72 in registry with the follower shoe 40 of the carriage operating bar 39. Springs 130, 130' are effective to draw the carriage rearwardly so that the shoe 40 is constantly engaged with the periphery of the eccentric cam 131. Cam 131 includes a sector 133 which is disposed a radial distance from the axis shaft 72 considerably less than the radial spacing of the sector 134 of said cam from said shaft. From the above description it will be obvious that when the sector 133 is rotated into registry with the follower shoe 40 the carriage will occupy its rearwardmost position and as the shaft 72 rotates the carriage will be gradually urged forward until the carriage will have reached its forwardmost position whereat the sector 134 is in registry with the shoe 40. Upon continued rotation of shaft 72 the carriage gradually moves rearwardly until the carriage again reaches its rearwardmost position, i.e., where the sector 133 registers with the shoe 40. It should be understood that the earn 131 is coordinated with cams 117 and 122 whereby when the carriage is in the rearwardmost position as determined by cam 131 the wedge members 110 are in their forward or clamp jaw releasing position and the hold-down levers are released to the key slot covering position. Promptly after the carriage begins its forward movement the Wedge members 110 are shifted rearwardly to jaw locking position and hold-down levers are pivoted clear of the slots.

In using the key cutter device, the operator inserts the blade or shank portion of the pattern or cut key into the key way slot in the clamp member 13 with the cut or bitted portion upwardly directed. Similarly the key blank is inserted into the key way slot 14 with a corresponding portion of the shank upwardly directed. In each instance, the shoulder portion of the key and blank adjacent the blade is thrust inwardly until said shoulder portions lie against the forwardmost portions of holddown levers 100. Insertion of the key and blank into the key ways is facilitated by the bevel portions 8%, 81b, 86b which guide the keys to the desired seated position in the clamps.

In my aforesaid copending application, there are described several forms of switching means for initiating the operating cycle of the key cutter therein described responsive to proper positioning of the key and key blank and particularly the shoulder portion thereof, in the key cutter clamps. The cycle initiating means therein described is equally adapted for use in conjunction with the cutter herein described and the use of said initiating means in conjunction with the present cutter is preferred but not essential. The initiation of an operating cycle in the herein described device may be effected by powerizing the motor M by any known switching means. When the motor M is actuated the milling or cutting wheel 59 is rapidly rotated, the shaft 72 forming the output of speed reducer 70 being thereby rotated at slow speeds. As shaft 72 rotates the carriage is urged forwardly or toward the key receptacles 12 and 13, the clamp jaws 82 being shifted to clamping position of the key and key blank and the hold-down levers being pivoted clear of any overlying relation to the key and key blank in the manner previously described. As the carriage continues to shift forward, the apex 65 of stylus 63 is brought into engagement with the patterned upper portion of the cut key secured in key way slot 15. As thestylus 63 scans 8 the bitted portion of the cut key the duplicator head 50 is raised and lowered against the weight of motor M and the tension of springs 68, 69, the miller or cutter 59 during this movement etching or filing into the key blank maintained in clamp 14 a bitting or pattern which thus corresponds with the pattern or bitting of the cut key. After completing its forward stroke the carriage is gradually retracted by action of springs 130 the duplicator head 50 in the course of such retractive movement again rising and falling in accordance with the pattern formed on the cut key held within slot 15. It will thus be appreciated that in the event there are deep cuts formed in the pattern key which were not correspondingly deeply etched into the blank on the forward stroke of the cutter, such cuts will be deepened and completed on the rearward or retractive stroke of the cutter. Optionally, but preferably, power to the motor M is shut off by a limit switch positioned to be engaged by the carriage 30 as the latter reaches its fully retracted position. The limit switch will thus automatically stop the motor M to prevent recycling of the key cutter. The positions of the various followers and cams at the forwardmost and the rearwardmost positions of the carriage 30 may be best understood by comparison of FIGURES 4 and 5, the former showing the part in the rearwardmost position and the latter in the forwardmost position of said carriage.

In FIGURE 8 there is shown an embodiment of the invention having novel cycle initiating mechanism. In this embodiment, like parts have been given like reference numerals.

As shown in FIGURE 8, the key hold down lever normally extends forwardly of the key and blank supports 12 and 13 in the path of the shoulder KS of the key and key blank. The shaft 101 which carries the lever 100 is permitted clearance for axial as well as rotary movement. Spring 104, in addition to the torsional force previously described for maintaining follower pin 121 against cam 122, is compressed between collar 107 and bracket 103, thereby normally urging the shaft and lever to the forward limiting position thereof. A microwitch MS is disposed closely adjacent the rearmost face of follower disk carried by shaft 101.

When a key or key blank is inserted into the keyway, the shoulder KS engages the forward face of the downwardly positioned hold down lever 100 and urges the latter axially inwardly or rearwardly, thus to carry the shaft 101 and disk 120 rearwardly and trip the microswitch MS.

Thus, it is assured that the device cannot be activated until the key has been fully inserted to urge the disk against the micro-switch.

Optionally, but preferably in the use of the embodiment of FIGURE 8, the micro-switches of the key and key blank are wired in series to assure that the cycle cannot be started unless both the micro-switches are closed, signifying proper insertion of both the key and key blank. Where a cycle starting device of the type illustrated in FIGURE 8 is employed, it will be necessary to utilize the circuit through the micro-switches to activate a hold circuit, which circuit will be effective to energize the motor throughout the operating cycle. This is necessary because, when the hold down levers are pivoted clear of the key shoulder, the spring 104 will urge the shaft 101 and lever 100 forwardly, opening the microswitch circuit.

In FIGURES 9 to 11 there is illustrated an embodiment in which a single cam 122 is utilized for operating both hold down levers 100. As shown in FIGURES 9 to 11 (wherein like parts have been given like reference numerals to the previously described embodiments), cam 122 is mounted on the righthandmost side of shaft 72. Shaft 101 is journalled at its forward end in bearing aperture 102 of said shaft having its rearmost end journalled in bracket 103 fixed to the base. A bell crank arm 300, having a roller follower portion 301 extends rearwardly from the rearmost end of the shaft, said roller portion being maintained against the lateral face of cam 122 by a torsion spring 104 having one end fixed in collar 107 secured to the shaft and having its other end fixed to bracket 103, as in the prior embodiments. Hold down lever 100 is fixed to the shaft 101 and is normally urged into covering relation of the key slot in-vise 13. A quadrant 302 isfixed to shaft 101, said quadrant having an aperture 303 in which inturned end 304 of drive rod 305 is pivotally secured.

Hold down 100a of a key vise 12 is fixed to stub shaft 101a rotatably mounted in said vise. is fixed to the stub shaft 101a, the quadrant 306 including an arcuate lost motion slot 307 within which the end 303 of drive rod 305 is movably secured. The end 3&8 lies adjacent the leading (lefthandmost, as viewed in FIG- URE 10) and 309 of slot 307 when the hold down 100a is in its lowermost position adjacent the top of vise 12. A butterfly spring 310 has one end 311 hooked about quadrant 306 (FIGURE 11), the opposite end of said spring being fixed to vise 12 to impart a counterclockwise torque to the hold down lever ltltla, normally to maintain the same in the downward (counterclockwise rotated) position against the top of vise 12 adjacentthe keyway 14- thereof.

From the description of this embodiment, it will be obvious that upon insertion of a key blank and key beneath hold downs 101 and 101a the blank and key will be seated in the slots 14 and 15, respectively, the blank by the pressure of spring 310 and the key by spring 104. Independent movement of hold down 100a is made possible by the use of oversized slot 307. When the device 'is activated to rotate cam 122, the rod 101 is rotated by the engagement of follower 301 against the operative face of suchcam. This draws rod 305 to the right, as viewed in FIGURES 9 and 10, continued movement of such rod causing end 308 to engage the end 309 of slot 307 and tilt hold down 1000 clockwise to expose thekey blank for cutting.

By the embodiment above described, the necessity for using an additional drum cam and follower is obviated.

The coordination of cams 117, 122 and 131 is assured by the provision of the squared cross shaft 72 since, through the use of such shaft together with cams having complemental squared drive apertures keyed to the shaft, rotary disorientation of the cams with respect to each other or the shaft is prohibited.

From the preceding description it will be observed that once a key and key blank are properly seated in the key and key blank clamps, no further steps need be taken to complete the formation of a cut key.

Having thus described my invention and illustrated its use, what I claim as new and seek to secure by Letters Patent is:

1. A key cutter device comprising a frame having a horizontally disposed track portion, a pair of key clamp means fixed to said frame adjacent a front end thereof, said clamp means being positioned to hold a pair of keys in side by side position parallel with said track portion, hold down means pivotally mounted adjacent each said clamp means and yieldably biased into covering position of said clampmeans, a carriage slidablymounted on said frame for linear movement forwardly and rearwardly along said track, spaced bearing means on said carriage, a cutter and tracer head assembly having spaced trunnion means pivotally seated in said bearing means of said carriage, said trunnion means being aligned normal to the direction of movement of said carriage on said track, a motor mounted on said head, a cutter wheel on said head operatively associated with said motor, a pattern tracer carried on said head, drive means including a power take off mounted on said frame and operatively associated with said motor, a cross shaft extending from said power take off and disposed normal to said track, a plurality of cam members keyed to said cross shaft in predetermined fixed A quadrant 306- position with respect thereto, follower means on said carriage, said key clamp means and said hold down means, each said follower means being operatively associated with a different camof said cross shaft, said cams and follower means being coordinated whereby, upon a single rotation of said cross shaft, said clamp means are sequentially shifted from key releasing to key clamping to key releasing positions, said hold down means areisequentially shifted from key engaging to key releasing to key holding positions, and said carriage is sequentially scanned for wardly and rearwardly across key elements carried in said clamp means in timed relationship to the operation of said key clamp means and key hold down means.

2. A device in accordance with claim 1 including spring means operatively associated with said frame and said carriage and urging the follower of said carriage into contact with a cam carried on said cross shaft.

3. A key cutter comprising a frame, a pair of key receptacles on said frame positioned to hold a key and a key blank in parallel, side by side relation, a shiftable jaw portion on each said receptacle, a carriage slidably mounted on said frame for reciprocal movement in a direction parallel with the axis of said keys, a cutter and tracer head pivotally mounted on said carriage and having spaced cutting and tracing means depending therefrom in potential direct contact with said blank and key, respectively, speed reducer means fixedly mounted with respect to said frame, flexible and extensible drive shaft means connected between said motor and an input shaft of said speed reducer, an output shaft driven by said speed reducer means and disposed normal to the axes of said key and key blank, spaced eccentric cam means fixed to said cross shaft to rotate therewith, spaced follower rods reciprocable in said frame, spring means urging said follower rods rearwardly against said cam means, wedge members fixed to the ends of said rods spaced from said cam means, one side of each said wedge means bearing against one said sliding jaw portion, and a steep release ledge portion on each said cam whereby, upon rotation of a selected magnitude of said shaft, said follower rods are abruptly released from said cams and shifted rearwardly by said springs to urge said edge members against said jaw members.

4. A key cutter comprising a frame, spaced seat portions fixed to said frame and positioned to hold a key and key blank in parallel side by side position, a shiftable clamp jaw portion on each said seat portion shiftable toward and away from clamping position thereon, wedge means disposed adjacent each said jaw portion and shiftable between rearward clamp jaw actuating and forward clamp jaw releasing positions, a cross shaft rotatable on an axis normal to the axis of said key and blank disposed rearwardly of said seat portions, spaced cam means carried by said shaft, follower elements fixed to said wedge means, spring means urging said follower elements rearwardly into engagement with the periphery of said cam means, said cam means each including a gradually inclined spring compression sector including successive portions spaced progressively further from the axis of rotation of said cross shaft and a follower release sector in trailing position with respect to said compression sector, the portions of said release sector being spaced closer to said axis of said cross shaft, the transition from said compression to said release sectors being abrupt whereby, when said release sector is rotated into registry with said follower elements, said wedge means are snapped abruptly by said spring means to said rearward position.

5. A key cutting device having a frame, a key seat on said frame and including fixed bottom and side wall portions, a clamp jaw shiftable toward and away from said side wall portion and yieldingly biased toward said wall, locking means adjacent said jaw and linearly reciprocable between jaw clamping and jaw releasing positions, a fol lower portion connected to said locking means, a cam mounted for rotation on an axis normal to the direction of movement of said locking means, said cam having a surface defining a gradual rise portion and an abrupt fall portion in trailing position with respect to said rise portion, and spring means interposed between said frame and said follower portion and biasing the latter toward said clamping position and against the surface of said cam.

6. In a key cutter including a frame having a pair of key receptacles, a cutter and tracer carriage on said frame and powerized means for reciprocating said carriage on said frame toward and away from said receptacles, key hold down means for seating a key and key blank in said receptacles comprising first and second key hold down levers, each pivotally mounted to one of said receptacles, cam means operatively associated with said powerized means, follower means operatively connected to said first hold down lever, spring means urging said follower means against said cam whereby said first hold down lever is yieldably maintained in operative position adjacent one said receptacle, second spring means urging said second hold down lever into operative position adjacent said other receptacle and connector means operatively associating said first and second hold down levers adapted to shift said second hold down lever to inoperative position clear of said other receptacle when said first hold down lever is shifted clear of said one receptacle by the cooperative action of said cam and said follower, said connector means providing a lost motion coupling between said first and second hold down levers, whereby movement imparted to said first hold down lever is not immediately communicated to said second lever.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A KEY CUTTER DEVICE COMPRISING A FRAME HAVING A HORIZONTALLY DISPOSED TRACK PORTION, A PAIR OF KEY CLAMP MEANS FIXED TO SAID FRAME ADJACENT A FRONT END THEREOF, SAID CLAMP MEANS BEING POSITIONED TO HOLD A PAIR OF KEYS IN SIDE BY SIDE POSITION PARALLEL WITH SAID TRACK PORTION, HOLD DOWN MEANS PIVOTALLY MOUNTED ADJACENT EACH SAID CLAMP MEANS AND YIELDABLY BIASED INTO COVERING POSITION OF SAID CLAMP MEANS, A CARRIAGE SLIDABLY MOUNTED ON SAID FRAME FOR LINEAR MOVEMENT FORWARDLY AND REARWARDLY ALONG SAID TRACK, SPACED BEARING MEANS ON SAID CARRIAGE, A CUTTER AND TRACER HEAD ASSEMBLY HAVING SPACED TRUNNION MEANS PIVOTALLY SEATED IN SAID BEARING MEANS OF SAID CARRIAGE, SAID TRUNNION MEANS BEING ALIGNED NORMAL TO THE DIRECTION OF MOVEMENT OF SAID CARRIAGE ON SAID TRACK, A MOTOR MOUNTED ON SAID HEAD, A CUTTER WHEEL ON SAID HEAD OPERATIVELY ASSOCIATED WITH SAID MOTOR, A PATTERN TRACER CARRIED ON SAID HEAD, DRIVE MEANS INCLUDING A POWER TAKE SAID MOTOR, A CROSS SHAFT EXTENDING FROM SAID POWER TAKE OFF AND DISPOSED NORMAL TO SAID TRACK, A PLURALITY OF CAM MEMBERS KEYED TO SAID CROSS SHAFT IN PREDETERMINED FIXED POSITION WITH RESPECT THERETO, FOLLOWER MEANS ON SAID CARRIAGE, SAID KEY CLAMP MEANS AND SAID HOLD DOWN MEANS, EACH SAID FOLLOWER MEANS BEING OPERATIVELY ASSOCIATED WITH A DIFFERENT CAM OF SAID CROSS SHAFT, SAID CAMS AND FOLLOWER MEANS BEING COORDINATED WHEREBY, UPON A SINGLE ROTATION OF SAID CROSS SHAFT, SAID CLAMP MEANS ARE SEQUENTIALLY SHIFTED FROM KEY RELEASING TO KEY CLAMPING TO KEY RELEASING POSITIONS, SAID HOLD DOWN MEANS ARE SEQUENTIALLY SHIFTED FROM KEY ENGAGING TO KEY RELEASING TO KEY HOLDING POSITIONS, AND SAID CARRIAGE IS SEQUENTIALLY SCANNED FORWARDLY AND REARWARDLY ACROSS KEY ELEMENTS CARRIED IN SAID CLAMP MEANS IN TIMED RELATIONSHIP TO THE OPERATION OF SAID KEY CLAMP MEANS AND KEY HOLD DOWN MEANS. 